This letterbook covers the period August-October 1891. Most of the letters are by Alfred O. Tate. There is also correspondence by Edison, Thomas Maguire, and John F. Randolph. Many of the letters relate to the manufacture and marketing of phonographs and cylinder recordings and to legal and financial dealings among the various phonograph companies. Included also are several letters about the phonograph exhibit at the Montreal Electrical Exhibition. Some of the correspondence pertains to mining and ore milling and to production problems at the New Jersey & Pennsylvania Concentrating Works. Other documents relate to electric lighting, the construction of central stations, production problems at the lamp factory, and the effects of electrocution on the human body. There are also documents concerning electric traction systems, including two cost estimates prepared for Henry Villard, and a few letters about the kinetograph and the Edison-Lalande battery. Some of the letters deal with Edison's liquidation of his stock in the Edison General Electric Co. and other personal financial matters. A few pertain to Mina Miller Edison. The book contains 702 numbered pages and an index. Approximately 20 percent of the book has been selected. Related documents for this time period can be found in LB-051.